1. Field of the Invention
This invention generally relates to a call forwarding system and, more particularly a call forwarding system for forwarding calls to a telephone not having its own direct dial number.
2. Description of the Prior Art
It is well known that a call forwarding system enables telephone calls directed to a particular telephone number to be redirected or forwarded to another telephone number. In particular, a user may program his or her telephone service such that any telephone call placed to the user""s telephone number will automatically reroute to a forwarded number chosen by the user, thereby causing the telephone at the forwarded number to ring.
In one particular implementation of call forwarding, calls may be forwarded within a private telephone network controlled by a private branch exchange (PBX) type system, such as found in many office environments. For example, an employee may forward his calls to the telephone of another employee within the telephone network. Typically, this is accomplished by the user simply pressing the appropriate feature button on the telephone or entering the appropriate code on the dual tone multi-frequency (DTMF) numeric keypad on the telephone to activate the call forwarding feature and then entering the appropriate internal extension to which the call should be forwarded. As described above, once the call forwarding feature has been enabled, telephone calls intended for the user will ring at the forwarded number.
In a second implementation of call forwarding, the company PBX or central office (CO) switch enables users to forward calls to virtually any telephone number that the user can directly dial. For example, as mentioned above, the user enters the appropriate code on the DTMF pad on the telephone to activate the call forwarding feature. However, instead of entering the internal extension, the user enters the direct dial number for the telephone to which the call is to be forwarded. Therefore, telephone calls intended for the user will be automatically forwarded and ring at the forwarded directory number.
However, wall forwarding cannot be used for forwarding calls to telephones that are connected to the Public Switched Telephone Network (PSTN) through a Key Telephone System (KTS), Hybrid Telephone System (HTS) or Private Branch Exchange (PBX) not having direct inward dial (DID) numbers. Such telephones only have internal extensions but do not have their own direct dial numbers. Accordingly, calls may only be forwarded to the main switchboard number, whereupon the caller must speak to the receptionist or go through the private system""s operator and request the called party by name or extension. Unfortunately, if the called party is not at at his or her own extension or if the caller does not know the name of the party being called, the receptionist has no way of forwarding the calls to the correct telephone number.
Therefore, there is a need for a call forwarding system wherein calls may proceed directly to a target telephone not having a direct dial number, without requiring the caller to interact with a receptionist or other similar function.
Briefly, the present invention relates to a call forwarding system for forwarding telephone calls to a target telephone not having a direct dial number. The call forwarding system includes an intelligent forwarding unit (IFU) for storing a forwarding direct dial number and extension number for accessing a target telephone and for connecting a forwarded call to a target telephone and a voice response unit having a DTMF tone detection unit for receiving the forwarded telephone call and for decoding the extension number of the target telephone.
A forwarding direct dial number and an extension number are provided by the user to the intelligent forwarding unit, which stores these numbers in a database or memory. When a telephone call is placed to the user""s telephone number, the call forwarding system receives the call and automatically dials the forwarding direct dial number from its memory. The voice receiving unit, which is located at the forwarded direct dial number, then picks up the call and establishes a connection. The intelligent forwarding unit, upon detecting establishment of the call, passes the extension number to the voice response unit over the connection. The voice response unit, after receiving the extension number, places a call to the target telephone and connects it to the current call. The intelligent forwarding unit, upon detecting pickup of the call at the dialed extension, connects the forwarded call to the target telephone connected to the extension number. An ANI decoding unit may also be included to enable the system to determine the telephone numbers of the calling parties.